What a difference two days make. Just before the opening of Saturday’s performance, the BSO management came out and announced that Morris had a bad cold and was withdrawing; taking his place would be Raymond Aceto, who had sung the relatively minor role of Pietro in rehearsals and opening night. Another singer would fill in Pietro’s role. In the chorus bleachers, I don’t think anyone was surprised that Morris wasn’t in, but there was a certain amount of anticipation for what would come next.

And Aceto’s performance made a world of difference. Where Morris played Fiesco as a menacing but relatively immobile force of nature, Aceto’s performance was resonant and dynamic, his acting vivid, and it sparked something in each of his collaborators. (I learned without surprise afterwards that he had sung the role at least once before, in Houston.) Everything snapped into focus in this production: for the chorus, crisp entrances and clearer diction; for the principals, more dramatic gestures and even better vocal control. Three cheers for Aceto, whose last-minute substitution saved the performance, if not the run.

So much for the performance. The opera itself is still working its way through me. Like a Shakespearian “problem play,” it does not categorize easily. Is it a political drama? Yes, but there’s also a substantial theme of family responsibility. Is it a comedy of mistaken identity? Well, it is right up until it turns tragic. (One backstage wit summarized the plot thus: “Boccanegra is a corsair, Fiesco hates him, Paolo is the bad guy, the tenor’s a bit dim, and the soprano needs to stop keeping secrets.”)

But the center of the play, first expounded in the council chamber scene and then echoed in Boccanegra’s reaction to his assassination, is about the restraint of power. Boccanegra could have set the hounds out and turned the mob on those that kidnapped his daughter and caused chaos in the streets, but instead settles the people and deals with the matter in private. Poisoned, he confronts his old enemy Fiesco and reveals Amelia’s identity, returning her to her family and settling an old grievance, and sets up a peaceful succession.

Is it then a political play? On paper, perhaps–and certainly, in the modern context, the temptation to make explicit parallels with modern history is strong. Ultimately, though, it’s the rediscovered connection between Boccanegra and Amelia that forms the pivot of the work, and for that one can only sit back and listen as the old doge’s love for the dead Maria is given new life in the duet with his daughter.